Expanding Feedstock Supplies of the Second Generation Bio-Fuels of Diesel-Engines

Abstract

Nowadays the first generation bio-fuels are already introduced in the European Union and amongst them the one used in Diesel-engines is the triglyceride containing feedstock derived product, the so-called biodiesel. However these fatty-acid-methyl-esters have multiple disadvantages (e.g.: poor oxidation and heat stability, lower energy content than the fossil derived diesel fuels, etc.) because of their chemical structure. Therefore it has become necessary to develop new bio-derived fuels on triglyceride supply, with other chemical structure. These bio-derived fuels are the second generation bio-fuels and amongst them the most promising product is the bio gas oil. The bio gas oil is a mixture of n- and i-paraffins (these are the primal components of the fossil diesel fuels also) in the gas oil boiling point range made from triglyceride containing feedstock. To ensure the eligible quantity and quality of bio gas oils, it is necessary to examine the utilization of other feedstocks with high triglyceride content. The European Union also urges the expanding of the feedstock supplies of the bio-derived motor fuels [COM(2006)34]. During our experimental work we examined the possibilities of the catalytic hydrogenation of mixtures of gas oil and lard or vegetable oil respectively, on NiMo/Al2O3 catalyst. Besides the examination of the reaction parameters (temperature: 360 °C, pressure: 80 bar, LHSV: 1.0 h-1 , H2/feedstock ratio: 600 Nm3/m3) which were found to be congenial for the catalytic conversion of vegetable oils for the conversion of the different, respectively lard or vegetable oil containing (0–10–20–30–50–100%) gas oil feedstocks we investigated the convertibility of the triglyceride part and the effect of the feedstock on the quality and the quantity of the product, furthermore the effect of the triglyceride in the feedstock on the desulphurisation, denitrification and dearomatisation. We determined that in the case of respectively 10% vegetable oil or lard containing feedstocks, the product was already an excellent bio-constituent containing diesel fuel blending component.